P1181

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. The engine may stop after starting, run unevenly and misfire, or idle speed too fast.

P1181

Fault symptoms

•	CHECK ENGINE.

•	The engine may stop after starting, run unevenly and misfire, or idle speed too fast.

On-Board Diagnostics

Type of diagnosis:

-	Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.

Enable criteria:

-	Engine running and closed loop active. One multiplicative and one additive adaptation has been performed.

Fault criteria:

-	Additive adaptation exceeding 4 mg/c for more than 30 s.

Dependents:

-	P0116, P0117, P0118, P0131, P0132, P0134, P0444, P0445 and P1105.

System reaction to a fault:

-

None.

OK report:

-

Provided that the fault criteria have not been fulfilled during the driving cycle, an OK report will be generated when the ignition is turned off and before the engine stops. Two types of OK report can be given: Type 1: If a diagnostic trouble code is already stored for the diagnosis and the same operating conditions have arisen (engine coolant above or below 71°C, engine speed ±375 rpm and load ±10%). Type 2: If a diagnostic trouble code is not already stored for the diagnosis or the same operating conditions have not arisen.

Fault handling: (See “Fault diagnosis, general” for more information.)

-

Type II.

Diagnostic help

At idling speed, the engine fuel requirement has been 25% greater than calculated by the control module using information from the mass air flow sensor.

Fault diagnosis first determines whether the pressure sensors show about the same value with the ignition ON, as the mass air flow sensor is later compared with the intake air pressure. If the pressure sensors are OK but the mass air flow sensor is incorrect then check for air leaks after the throttle and thereafter, change the mass air flow sensor.

If the air quantity is OK, then the fuel supply is checked, i.e. pressure, response, pump flow and finally the injectors.

Functions in the diagnostic tool related to the fault:

•	Diagnostic status for the diagnosis.

•	O2S 1, unit V

•	Additive Adaptation, unit mg/c.

•	Closed loop, unit %.

•	Purge Adaptation, unit %.

•	Air mass deviation from calculated, unit %.

See also the description of readings in ”Fault diagnosis, general” for more information.

See .